WO 2010/100594 A2 discloses a method and a system for processing images of living beings. The method comprises the steps of:                obtaining a sequence of digital images taken at consecutive points in time;        selecting at least one measurement zone comprising a plurality of image points, wherein        the step of selecting at least one measurement zone includes analyzing information based on pixel data of a plurality of image parts in at least one of the images, each image part including at least one image point, and selecting each measurement zone from contiguous parts determined to have similar characteristics; and        for each measurement zone, obtaining a signal representative of at least variations in a time-varying average value of a combination of pixel values at at least a number of the image points for use in determining at least one of a presence and a frequency value of at least one peak in a spectrum of the signal corresponding to a frequency of a periodic physiological phenomenon.        
This document further discloses several refinements of the method. In general, in the field of image processing enormous progress was made in that profound analyses of the recorded data were enabled. In this context, it could be envisaged to extract information from recorded data in a way as to enable detailed conclusions regarding the personality or even the well-being of an observed living individual.
However, as the recorded data, such as captured reflected or emitted electromagnetic radiation, especially recorded image frames, always comprises, beside of the desired signal to be extracted therefrom, further signal components deriving from overall disturbances, by way of example, such as noise due to changing luminance conditions or a movement of observed objects, a detailed precise extraction of the desired signals still poses major challenges for the processing of such data.
This applies in particular when amplitudes and/or nominal values of disturbing signal components are much larger than amplitudes and/or nominal values of desired signal components to be extracted. Potentially, the magnitude of difference between the respective components can be expected to even comprise several orders.
A possible approach to this challenge may be directed to providing well-prepared and steady ambient conditions when capturing a signal of interest in which the desired signal component is embedded so as to minimize disturbing signal components overlaying the signal. However, such laboratory conditions cannot be transferred to everyday field applications as high efforts and preparation work would be required therefor.
The required preparation might comprise, by way of example, installation and orientation of several standard light sources and, moreover, measures for fixation of the object to be observed in order to avoid disturbing movements responsible for an even larger noise level.